Latch and pry-out mechanism for disconnect switches



April 1965 G. R. MCCLOUD ETAL 3,248,509

LATCH AND FRY-OUT MECHANISM FOR DISCONNECT SWITCHES 2 Sheets-Sheet 1 Filed Oct. 28, 1963 M w m? N M w n r N 4 r M6 M 4 6 GAY April 26, 1966 G. R. MCCLOUD ETAL 3,248,509

LATCH AND FRY-OUT MECHANISM FOR DISCONNEGT SWITCHES Filed Oct. 28, 1963 2 Sheets-Sheet 2 INVENTORS. 6ae6 K MQam? United States Patent 3,248,569 LATCH AND FRY-OUT MECHANISM FOR DHSQONNECT SWITCHES George R. McCloud, South Milwaukee, and Arthur C.

Gavlitta, Milwaukee, Wis., assignors to McGraw- Edison Company, Milwaukee, Wis., a corporation of Delaware Filed Oct. 28, 1963, Ser. No. 319,366 3 Claims. (Cl. 20t)162) This invention relates to disconnect switches and more particularly to an improved structure including a latching and pry-out mechanism for such switches.

The disconnect switch of the present invention is provided with a lever having a pull ring that upon actuation provides a mechanical advantage to sequentially pry out the latch and thereafter also afford a prying action to initiate pivoting of the switch blades toward a disconnected. position. This feature in combination with a structure wherein an iceaccumulation is substantially completely in shear rather than in compression with regard to the switch parts causes the switch to be operable under severe icing conditions with less applied force than necessary in heretofore known designs. In addition, the disconnect switch of this invention is manufactured almost exclusively of economical strip materials to provide greater economy and improved conductivity.

It is an object of this invention to provide an improved latch and pry-out mechanism for a disconnect switch.

It is also an object of this invention to provide a disconnect switch requiring less force to operate when subject to icing conditions.

It is also an object of this invention to provide a latch and pry-out mechanism that provides a high mechanical advantage and breaks ice in shear rather than in compression to afford ease of operation.

It is a further object of the invention to provide a device formed primarily of highly conductive strip material and stamped parts.

These and other objects and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawings wherein:

FIG. 1 is a side elevation partially broken away of the disconnect switch of this invention shown in the fully closed position;

FIG. 2 is a plan view of the switch of FIG. 1;

FIG. 3 is a partial sectional elevation taken along line 33 of FIG. 1;

FIG. 4 is a side elevation of the latch and pry-out member portion of the disconnect switch shown in a closed but unlatched position prior to the pivoting of the blade assembly; and

FIG. 5 is a partial side elevation of the disconnect switch of FIG. 1 shown in the unlatched position with the blade assembly partially pivoted and a phantom view of the prying action of the lever initiating the pivoting of the blade assembly.

Referring to FIGS. 1 and 2, the disconnect switch assembly is shown mounted on a pair of porcelain insulators 12, 13 which are supported on a common wing channel base 14. A stationary terminal assembly 17 is supported on the insulator 13 which includes a continuous strip 19 of conductive material that has terminal'pad 20 at one end and terminates at its opposite end in the upright hinge member 21. A brace 22 has one end which extends through a slotted opening in the strip 19 with a turned portion 23 engaging the underside and filters 24 abutting the upper surfaces of strip 19 and the opposite end secured to the upright hinge member by the rivet 25.

Mounted on the insulator 12 is a second terminal as- 3,248,509 Patented Apr. 26, 1966 "Ice senibly 29 which is similarly comprised of a strip of conductive material 30 one end of which forms a terminal pad 31 and the opposite end of which provides a fixed contact 32. Also connected to the insulator by the same securing bolts 33 is a metal plate 35 which has an upwardly turned transverse marginal edge 36 which provides a stop for the switch blades 40 and 41 and downwardly turned longitudinal margins 42 that afford greater rigidity. The fixed contact 32 has a latch portion 44 that is formed by pierce extruding a portion of the strip material of the contact. V

A pin 46 extends through coaxial openings in blades 40, 41 and pierce extruded openings in upright hinge member 21 to pivotally support the blades on terminal assembly 17 in abutting relation to the transverse edge surfaces of member 21. At each end of the pin 46 is a threaded terminal section on which are mounted a securing nut 47 and a jam nut 48 with a spring washer 49 provided between the securing nut and the confronting blade surface to secure continuous optimum contact between the switch blades 40, 41 and the edge surfaces of the upright hinge member 21.

At the latch end of the switch blades is a lever 50 formed of. two pieces of sheet material which are spot welded together at one end with a pull ring 51 formed therein. The opposite end is of a bifurcated form with the parallel fork portions 53 extending along either transverse side of the switch blades. A pin 55 extends through openings in the switch blades 40, 41 and lever 50 to pivotally interconnect the lever to the blades. The switch blades 40, 41 have transversely confronting slotted portions 57 with a latch bar 60 extending therethrough. A pair of scar springs 61 have end portions extending respectively through openings in the ends of the pin 55 and latch bar 60 and serve to both retain the pin 55 and bar 60 against removal and urge the latch bar 60 within the confines of the slots 57.toward the pin 55. The bifurcated portion 53 of the lever 50 is provided with inwardly turned tabs 63 which serve to limit pivotal movement of the lever in a counterclockwise direction by abutting the respectively confronting edge surfaces of the switch blades as viewed in FIG. 1 and carnming surfaces are provided by the edges at 65 and 66 which respectively engage the latch bar 60 and the plate 35 upon movement of the lever 50in a clockwise direction. The switch blades are additionally interconnected by pins 68 and 69 which limit movement of the blades apart from one another with each pin respectively surrounded by a sleeve 70, 71 intermediate the blades to define a minimum spacing therebetween. At the latch end of the switch blades a pin 73 is secured through openings in the blade and is provided with a compression spring 75 which urges the blade ends toward one another to atford optimum electrical contact between the blades 40, 41 and the stationary or fixed contact 32.

in operation the blades 40, 41 of the disconnect switch are moved from a closed position as illustrated in FIG. 1 to an open position 'by pulling on the ring 51 which force would normally be applied in the first quadrant (from vertically upward to directly to the right, as viewed in FIG. 1) when the switch is mounted in either of the customary positions. As the lever 50 is rotated in 'a clockwise direction the cam surface 65 engages the latch bar 60 and pries it within the confines of the slots 57 away from a position of underlying latching engagement with the latch portion 44 of the stationary contact 32 to a position shown in FIG. 4. sequentially thereafter, further clockwise movement of the lever will cause the cam surfaces 66 to contact the plate 35 as seen in the phantom view portion of FIG. 5 and to 'begina prying action that provides a mechanical advantage to initiate pivoting of the switch blades about the axis of pin 46. Thus, not only 3 r is a prying action afforded with respect to unlatching but a prying action is also provided where necessary to break the blades free when conditions such as icing causes resistance to the opening of the switch. Under icing conditions, any ice that occurs in positions to cause compressive contact with moving parts abut edges of relatively thin structures of strip or sheet material such as the edges of the lever portions 53 and as a result the principal obstructions to movement and switch operation would be presented by ice occurring in shear which is more easily broken free.

Although but one embodiment has been shown and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A disconnect switch comprising first and second spaced stationary terminal assemblies; a blade assembly having a pair of transversely spaced blades interconnected for unitary pivotal movement about a transverse axis, said blade assembly being pivotally connected to said first terminal assembly about said transverse axis; a latch portion presented by said second stationary terminal assembly; said switch blades each having a longitudinally extending transversely confronting slotted opening therein adjacent said second terminal assembly latch portion; a rod ex-,-

blades, said forked portions having edge surfaces that 4 sequentially engage said rod and said second stationary terminal assembly when said'lever is pivoted in one direction to move said rod from a latch portion engaging position and thereafter to pry said blade assembly away from said closed position.

2. The disconnect switch of claim 1 wherein said rod urges said lever in the opposite of said one direction.

3'. A disconnect switch comprising a hinge member; a blade assembly including a pair of spaced generally parallel blade members interconnected for unitary pivotal movernent about a transverse axis, said blade assembly being pivotally connected to said hinge member about said transverse axis; a terminal assembly presenting a latching portion; a longitudinally extending slotted opening in each of said blade members; a first rod extending through said slotted openings and engageable with said latching portion to retain said assemblies in latched engagement with one another; a bifurcated lever formed of strip material with generally parallel projecting portions disposed transversely outwardly adjacent and substantially parallel to the major surfaces of said blade members and pivotally connected thereto about a second rod; a pair of sear springs each interconnecting said first and second rods for retaining said first rod and biasing said first rod toward a latching portion engaging position; first camming surfaces presented by the edge surfaces of said parallel projecting portions engaging said first rod and second camming surfaces presented by the edge surfaces of said projecting portions engageable with said terminal assembly, said lever being pivotable in one direction to cam said first rod away from a latching portion engaging position and thereafter to cause said blade assembly to rotate about said transverse axis.

References Cited by the Examiner UNITED STATES PATENTS 1,864,548 6/1932 Nordhem 200169 2,226,818 12/ 1940 Heinrich 200162 2,288,134 6/1942 Hoye 200-162 2,803,726 8/1957 Gilliland 200-462 2,917,609 12/1959 Mikos 200162 X KATHLEEN H. CLAFFY, Primary Examiner.

ROBERT K. SCHAEFER, WILLIAM C. GARVERT,

Examiners. 

1. A DISCONNECT SWITCH COMPRISING FIRST AND SECOND SPACED STATIONARY TERMINAL ASSEMBLIES; A BLADE ASSEMBLY HAVING A PAIR OF TRANSVERSELY SPACED BLADES INTERCONNECTED FOR UNITARY PIVOTAL MOVEMENT ABOUT A TRANSVERSE AXIS, SAID BLADE ASSEMBLY BEING PIVOTALLY CONNECTED TO SAID FIRST TERMINAL ASSEMBLY ABOUT SAID TRANSVERSE AXIS; A LATCH PORTION PRESENTED BY SAID SECOND STATIONARY TERMINAL ASSEMBLY; SAID SWITCH BLADES EACH HAVING A LONGITUDINALLY EXTENDING TRANSVERSELY CONFRONTING SLOTTED OPENING THEREIN ADJACENT SAID SECOND TERMINAL ASSEMBLY LATCH PORTION; A ROD EXTENDING THROUGH SAID SLOTTED OPENINGS AND CARRIED BY SAID BLADE ASSEMBLY, SAID ROD BEING MOVABLE IN A DIRECTION GENERALLY PERPENDICULAR TO THE AXIS THEREOF AND ENGAGABLE WITH SAID LATCH PORTION TO PROVIDE SOLE LATCHING ENGAGEMENT TO RETAIN SAID BLADE ASSEMBLY IN A CLOSED POSITION; BIASING MEANS URGING SAID ROD TOWARD A LATCH PORTION ENGAGING POSITION; AND A BIFURCATED ACTUATING LEVER PIVOTALLY CONNECTED TO SAID BLADE ASSEMBLY AND PRESENTING THIN GENERALLY PARALLEL FORKED PORTIONS EXTENDING RESPECTIVELY ADJACENT AND SUBSTANTIALLY PARALLEL TO SAID PAIR OF BLADES, SAID FORKED PORTIONS HAVING EDGE SURFACES THAT SEQUENTIALLY ENGAGED SAID ROD AND SAID SECOND STATIONARY TERMINAL ASSEMBLY WHEN SAID LEVER IS PIVOTED IN ONE DIRECTION TO MOVE SAID ROD FORM A LATCH PORTION ENGAGING POSITION AND THEREAFTER TO PRY SAID BLADE ASSEMBLY AWAY FROM SAID CLOSED POSITION. 